Isotopes of berkelium

Actinides and fission products by half-life v t e
Actinides^[1] by decay chain				Half-life range (y)	Fission products of ²³⁵U by yield^[2]
4n	4n+1	4n+2	4n+3		Fission products of ²³⁵U by yield^[2]
4n	4n+1	4n+2	4n+3			4.5–7%	0.04–1.25%	<0.001%
²²⁸Ra^№				4–6	†		¹⁵⁵Eu^þ
²⁴⁴Cm	²⁴¹Pu^ƒ	²⁵⁰Cf	²²⁷Ac^№	10–29		⁹⁰Sr	⁸⁵Kr	^113mCd^þ
²³²U^ƒ		²³⁸Pu^№	²⁴³Cm^ƒ	29–97		¹³⁷Cs	¹⁵¹Sm^þ	^121mSn
²⁴⁸Bk^[3]	²⁴⁹Cf^ƒ	^242mAm^ƒ		141–351	No fission products have a half-life in the range of 100–210 k years ...
	²⁴¹Am		²⁵¹Cf^ƒ^[4]	430–900
		²²⁶Ra^№	²⁴⁷Bk	1.3 k – 1.6 k
²⁴⁰Pu	²²⁹Th^№	²⁴⁶Cm	²⁴³Am	4.7 k – 7.4 k
	²⁴⁵Cm^ƒ	²⁵⁰Cm		8.3 k – 8.5 k
			²³⁹Pu^ƒ№	24.1 k
		²³⁰Th^№	²³¹Pa^№	32 k – 76 k
²³⁶Np^ƒ	²³³U^ƒ№	²³⁴U^№		150 k – 250 k	‡	⁹⁹Tc^₡	¹²⁶Sn
²⁴⁸Cm		²⁴²Pu		327 k – 375 k			⁷⁹Se^₡
				1.53 M		⁹³Zr
	²³⁷Np^№			2.1 M – 6.5 M		¹³⁵Cs^₡	¹⁰⁷Pd
²³⁶U^№			²⁴⁷Cm^ƒ	15 M – 24 M			¹²⁹I^₡
²⁴⁴Pu^№				80 M	... nor beyond 15.7 M years^[5]
²³²Th^№		²³⁸U^№	²³⁵U^ƒ№	0.7 G – 14.1 G	... nor beyond 15.7 M years^[5]
Legend for superscript symbols ₡ has thermal neutron capture cross section in the range of 8–50 barns ƒ fissile m metastable isomer № naturally occurring radioactive material (NORM) þ neutron poison (thermal neutron capture cross section greater than 3k barns) † range 4–97 y: Medium-lived fission product ‡ over 200,000 y: Long-lived fission product

Berkelium (Bk) is an artificial element, and thus a standard atomic mass cannot be given. Like all artificial elements, it has no stable isotopes. The first isotope to be synthesized was ²⁴³Bk in 1949. There are 20 known radioisotopes, from ²³⁵Bk to ²⁵⁴Bk, and 6 nuclear isomers. The longest-lived isotope is ²⁴⁷Bk with a half-life of 1,380 years.

Table[edit]

nuclide symbol	Z(p)	N(n)	isotopic mass (u)	half-life	decay mode(s)^[6]^{[n 1]}	daughter isotope(s)	nuclear spin
nuclide symbol	excitation energy			half-life	decay mode(s)^[6]^{[n 1]}	daughter isotope(s)	nuclear spin
²³⁵Bk	97	138	235.05658(43)#	20# s	α	²³¹Am
²³⁵Bk	97	138	235.05658(43)#	20# s	β⁺	²³⁵Cm
²³⁶Bk	97	139	236.05733(43)#	1# min	α	²³²Am
²³⁶Bk	97	139	236.05733(43)#	1# min	β⁺	²³⁶Cm
²³⁷Bk	97	140	237.05700(24)#	1# min	α	²³³Am	7/2+#
²³⁷Bk	97	140	237.05700(24)#	1# min	β⁺ (rare)	²³⁷Cm	7/2+#
²³⁸Bk	97	141	238.05828(31)#	2.40(8) min	α	²³⁴Am
					β⁺, SF (.048%)	(various)
					β⁺ (rare)	²³⁸Cm
²³⁹Bk	97	142	239.05828(25)#	3# min	α	²³⁵Am	7/2+#
²³⁹Bk	97	142	239.05828(25)#	3# min	β⁺	²³⁹Cm	7/2+#
²⁴⁰Bk	97	143	240.05976(16)#	4.8(8) min	β⁺ (90%)	²⁴⁰Cm
					α (10%)	²³⁶Am
					β⁺, SF (.002%)	(various)
²⁴¹Bk	97	144	241.06023(22)#	4.6(4) min	α	²³⁷Am	(7/2+)
²⁴¹Bk	97	144	241.06023(22)#	4.6(4) min	β⁺ (rare)	²⁴¹Cm	(7/2+)
²⁴²Bk	97	145	242.06198(22)#	7.0(13) min	β⁺ (99.99%)	²⁴²Cm	2−#
²⁴²Bk	97	145	242.06198(22)#	7.0(13) min	β⁺, SF (3×10⁻⁴%)	(various)	2−#
^242mBk	200(200)# keV			600(100) ns
²⁴³Bk	97	146	243.063008(5)	4.5(2) h	β⁺ (99.85%)	²⁴³Cm	(3/2−)
²⁴³Bk	97	146	243.063008(5)	4.5(2) h	α (.15%)	²³⁹Am	(3/2−)
²⁴⁴Bk	97	147	244.065181(16)	4.35(15) h	β⁺ (99.99%)	²⁴⁴Cm	(4−)#
²⁴⁴Bk	97	147	244.065181(16)	4.35(15) h	α (.006%)	²⁴⁰Am	(4−)#
²⁴⁵Bk	97	148	245.0663616(25)	4.94(3) d	EC (99.88%)	²⁴⁵Cm	3/2−
²⁴⁵Bk	97	148	245.0663616(25)	4.94(3) d	α (.12%)	²⁴¹Am	3/2−
²⁴⁶Bk	97	149	246.06867(6)	1.80(2) d	β⁺ (99.8%)	²⁴⁶Cm	2(−)
²⁴⁶Bk	97	149	246.06867(6)	1.80(2) d	α (.2%)	²⁴²Am	2(−)
²⁴⁷Bk	97	150	247.070307(6)	1.38(25)×10³ y	α	²⁴³Am	(3/2−)
²⁴⁷Bk	97	150	247.070307(6)	1.38(25)×10³ y	SF (rare)	(various)	(3/2−)
²⁴⁸Bk	97	151	248.07309(8)#	>300 y^[7]	α	²⁴⁴Am	6+#
^248mBk	30(70)# keV			23.7(2) h			1(−)
²⁴⁹Bk^{[n 2]}	97	152	249.0749867(28)	330(4) d	β⁻	²⁴⁹Cf	7/2+
					α (.00145%)	²⁴⁵Am
					SF (4.7×10⁻⁸%)	(various)
^249mBk	8.80(10) keV			300 µs			(3/2−)
²⁵⁰Bk	97	153	250.078317(4)	3.212(5) h	β⁻	²⁵⁰Cf	2−
^250m1Bk	35.59(5) keV			29(1) µs			(4+)
^250m2Bk	84.1(21) keV			213(8) µs			(7+)
²⁵¹Bk	97	154	251.080760(12)	55.6(11) min	β⁻	²⁵¹Cf	(3/2−)#
²⁵¹Bk	97	154	251.080760(12)	55.6(11) min	α (10⁻⁵%)	²⁴⁷Am	(3/2−)#
^251mBk	35.5(13) keV			58(4) µs			(7/2+)#
²⁵²Bk	97	155	252.08431(22)#	1.8(5) min	β⁻	²⁵²Cf
²⁵²Bk	97	155	252.08431(22)#	1.8(5) min	α	²⁴⁸Am
²⁵³Bk	97	156	253.08688(39)#	10# min	β⁻	²⁵³Cf
²⁵⁴Bk	97	157	254.09060(32)#	1# min	β⁻	²⁵⁴Cf

^ Abbreviations:
EC: Electron capture
IT: Isomeric transition
SF: Spontaneous fission
^ Easiest isotope to synthesize

Notes[edit]

Values marked # are not purely derived from experimental data, but at least partly from systematic trends. Spins with weak assignment arguments are enclosed in parentheses.
Uncertainties are given in concise form in parentheses after the corresponding last digits. Uncertainty values denote one standard deviation, except isotopic composition and standard atomic mass from IUPAC, which use expanded uncertainties.

References[edit]

^ Plus radium (element 88). While actually a sub-actinide, it immediately precedes actinium (89) and follows a three-element gap of instability after polonium (84) where no isotopes have half-lives of at least four years (the longest-lived isotope in the gap is radon-222 with a half life of less than four days). Radium's longest lived isotope, at 1,600 years, thus merits the element's inclusion here.
^ Specifically from thermal neutron fission of U-235, e.g. in a typical nuclear reactor.
^ Milsted, J.; Friedman, A. M.; Stevens, C. M. (1965). "The alpha half-life of berkelium-247; a new long-lived isomer of berkelium-248". Nuclear Physics 71 (2): 299. doi:10.1016/0029-5582(65)90719-4.
"The isotopic analyses disclosed a species of mass 248 in constant abundance in three samples analysed over a period of about 10 months. This was ascribed to an isomer of Bk²⁴⁸ with a half-life greater than 9 y. No growth of Cf²⁴⁸ was detected, and a lower limit for the β⁻ half-life can be set at about 10⁴ y. No alpha activity attributable to the new isomer has been detected; the alpha half-life is probably greater than 300 y."
^ This is the heaviest isotope with a half-life of at least four years before the "Sea of Instability".
^ Excluding those "classically stable" isotopes with half-lives significantly in excess of ²³²Th; e.g., while ^113mCd has a half-life of only fourteen years, that of ¹¹³Cd is nearly eight quadrillion years.
^ "Universal Nuclide Chart". nucleonica. (registration required (help)).
^ Milsted, J.; Friedman, A. M.; Stevens, C. M. (1965). "The alpha half-life of berkelium-247; a new long-lived isomer of berkelium-248". Nuclear Physics 71 (2): 299. doi:10.1016/0029-5582(65)90719-4. edit

Isotope masses from:
- G. Audi; A. H. Wapstra; C. Thibault; J. Blachot; O. Bersillon (2003). "The NUBASE evaluation of nuclear and decay properties" (PDF). Nuclear Physics A 729: 3–128. Bibcode:2003NuPhA.729....3A. doi:10.1016/j.nuclphysa.2003.11.001.
Isotopic compositions and standard atomic masses from:
- J. R. de Laeter; J. K. Böhlke; P. De Bièvre; H. Hidaka; H. S. Peiser; K. J. R. Rosman; P. D. P. Taylor (2003). "Atomic weights of the elements. Review 2000 (IUPAC Technical Report)". Pure and Applied Chemistry 75 (6): 683–800. doi:10.1351/pac200375060683.
- M. E. Wieser (2006). "Atomic weights of the elements 2005 (IUPAC Technical Report)". Pure and Applied Chemistry 78 (11): 2051–2066. doi:10.1351/pac200678112051. Lay summary.
Half-life, spin, and isomer data selected from the following sources. See editing notes on this article's talk page.
- G. Audi; A. H. Wapstra; C. Thibault; J. Blachot; O. Bersillon (2003). "The NUBASE evaluation of nuclear and decay properties" (PDF). Nuclear Physics A 729: 3–128. Bibcode:2003NuPhA.729....3A. doi:10.1016/j.nuclphysa.2003.11.001.
- National Nuclear Data Center. "NuDat 2.1 database". Brookhaven National Laboratory. Retrieved September 2005.
- N. E. Holden (2004). "Table of the Isotopes". In D. R. Lide. CRC Handbook of Chemistry and Physics (85th ed.). CRC Press. Section 11. ISBN 978-0-8493-0485-9.

Isotopes of curium	Isotopes of berkelium	Isotopes of californium
Table of nuclides

[7] Abbreviations:
EC: Electron capture
IT: Isomeric transition
SF: Spontaneous fission

[9] Easiest isotope to synthesize

[1] Plus radium (element 88). While actually a sub-actinide, it immediately precedes actinium (89) and follows a three-element gap of instability after polonium (84) where no isotopes have half-lives of at least four years (the longest-lived isotope in the gap is radon-222 with a half life of less than four days). Radium's longest lived isotope, at 1,600 years, thus merits the element's inclusion here.

[2] Specifically from thermal neutron fission of U-235, e.g. in a typical nuclear reactor.

[3] Milsted, J.; Friedman, A. M.; Stevens, C. M. (1965). "The alpha half-life of berkelium-247; a new long-lived isomer of berkelium-248". Nuclear Physics 71 (2): 299. doi:10.1016/0029-5582(65)90719-4.
"The isotopic analyses disclosed a species of mass 248 in constant abundance in three samples analysed over a period of about 10 months. This was ascribed to an isomer of Bk²⁴⁸ with a half-life greater than 9 y. No growth of Cf²⁴⁸ was detected, and a lower limit for the β⁻ half-life can be set at about 10⁴ y. No alpha activity attributable to the new isomer has been detected; the alpha half-life is probably greater than 300 y."

[4] This is the heaviest isotope with a half-life of at least four years before the "Sea of Instability".

[5] Excluding those "classically stable" isotopes with half-lives significantly in excess of ²³²Th; e.g., while ^113mCd has a half-life of only fourteen years, that of ¹¹³Cd is nearly eight quadrillion years.

[6] "Universal Nuclide Chart". nucleonica. (registration required (help)).

[8] Milsted, J.; Friedman, A. M.; Stevens, C. M. (1965). "The alpha half-life of berkelium-247; a new long-lived isomer of berkelium-248". Nuclear Physics 71 (2): 299. doi:10.1016/0029-5582(65)90719-4. edit

[1]

[2]

[3]

[4]

[5]

[6]

[n 1]

[7]

[n 2]

v t e Isotopes of the chemical elements
1 H																	2 He
3 Li	4 Be											5 B	6 C	7 N	8 O	9 F	10 Ne
11 Na	12 Mg											13 Al	14 Si	15 P	16 S	17 Cl	18 Ar
19 K	20 Ca	21 Sc	22 Ti	23 V	24 Cr	25 Mn	26 Fe	27 Co	28 Ni	29 Cu	30 Zn	31 Ga	32 Ge	33 As	34 Se	35 Br	36 Kr
37 Rb	38 Sr	39 Y	40 Zr	41 Nb	42 Mo	43 Tc	44 Ru	45 Rh	46 Pd	47 Ag	48 Cd	49 In	50 Sn	51 Sb	52 Te	53 I	54 Xe
55 Cs	56 Ba		72 Hf	73 Ta	74 W	75 Re	76 Os	77 Ir	78 Pt	79 Au	80 Hg	81 Tl	82 Pb	83 Bi	84 Po	85 At	86 Rn
87 Fr	88 Ra		104 Rf	105 Db	106 Sg	107 Bh	108 Hs	109 Mt	110 Ds	111 Rg	112 Cn	113 Uut	114 Fl	115 Uup	116 Lv	117 Uus	118 Uuo

		57 La	58 Ce	59 Pr	60 Nd	61 Pm	62 Sm	63 Eu	64 Gd	65 Tb	66 Dy	67 Ho	68 Er	69 Tm	70 Yb	71 Lu
		89 Ac	90 Th	91 Pa	92 U	93 Np	94 Pu	95 Am	96 Cm	97 Bk	98 Cf	99 Es	100 Fm	101 Md	102 No	103 Lr
Table of nuclides Categories: Isotopes Tables of nuclides Metastable isotopes Isotopes by element

Isotopes of berkelium

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